Q-272. Evaluation of Spray-Applied Sporicidal Decontamination Technologies against Bacillus anthracis and Surrogate Spores on Indoor Surfaces

J. Rogers1, W. Richter1, Y. Choi1, A. Shesky1, M. Taylor1, J. Wood2;
1Battelle Mem. Inst., Columbus, OH, 2U.S. EPA, Research Triangle Park, NC.

The U.S. Environmental Protection Agency’s (EPA) National Homeland Security Research Center (NHSRC) Technology Testing and Evaluation Program (TTEP) helps to protect human health and the environment from adverse impacts of terrorist acts by carrying out performance tests on homeland security technologies. This study presents both quantitative and qualitative results for ten spray-applied sporicidal technologies that were evaluated for their effectiveness in decontamination of surfaces. Test coupons representing indoor materials included industrial carpet, pine wood, glass, laminate, galvanized metal, painted wallboard paper, and painted concrete. Test materials were spot inoculated (1x108 CFU) with Bacillus anthracis Ames, B. anthracis Sterne, B. subtilis (ATCC 19659), or Geobacillus stearothermophilus (ATCC 12980). Testing was performed using a spray application test apparatus developed by Battelle under TTEP. This test apparatus allowed for precise control of parameters that could affect the efficacy of spray-applied decontamination technologies, such as the total deposited mass of spray-applied technology. For the ten technologies, a screening test was used to down-select the four most efficacious technologies that were subsequently subjected to further in-depth decontamination efficacy testing. Following the application of each liquid technology and the required contact time, viable B. anthracis spores were extracted, serially diluted, and spread onto semi-solid growth medium. Results obtained in the screening test showed varying decontamination efficacies for the ten technologies ranging from <1.0 to ≥ 7.8 log reductions. Decontamination efficacy varied by technology, bacterial spore species, and coupon material. In general, treatment of inoculated coupons with sprayed pH-amended bleach and the four down-selected technologies yielded higher log reductions on non-porous compared to porous materials.